Reenforcing bar for cementitious materials



H. H. MUIR.

I REENFORCING BAR FOR CEMENTITIOUS MATERIALS.

APPLICATION FILED MAY I7. 1919.

1 ,41 6,1 1 7 Patented May 16, 192-2.

HERBERT n. vrurn, or 'wnsrrnani sr nirves, ILLINOIS.

nnnnroaorne- BAR; ro'n. onmiinrrrrons 5 MATERIALS.

'1 0 all whom it may concern:

Be it known that I, HERBERTL H. Morn, a

' citizen of the United States, and aresident bedded in or surrounded .by the concrete,

and as the principal forces upon. the structure are external, they are necessarily transmitted tothe metal'through the concrete. This transmission of the forces 1s accorn-- .plished by means of theresistance to d1splacement of the bars in a cementitious' body bythe surface contact ofithe bar with the ce mentitious material after the latter has thoroughly set or hardened. This resistance between the contacting surfaces of the metallic bar. and the cementitious material is due, in structures of reenforcing bars now commonly used, to the adhesion of the cementitious material to the relatively smooth surface of the bar. The bar is naturally formed with small surface irregularities which are hardly perceptible, and-in some instances surface projections have been formed upon the bar for engagement in a cementitious body.

In all heretofore constructed forms of.

smooth and deformed bars, there exists, to a more or less degree, certain surface areas which lie substantially parallel to the axis of the bar, and which therefore only partially offset the disrupting of the cementitious' structure when submitted to stress.

In all prior forms of reenforcing bars forces tending to dislodge reenforcing bars are repelled only or largely by resistance of adhesion stressing the meeting surfaces of t sides thereof.

Specification of Iietters Pat t d Eg 1 19 Application filedMay 17, 1919; senai no. 2925791;

in parallelism with the axis of the bar, have this disrupting tendency and thus do not carry out the complete economic functionof the concrete structure.

It is an object of" the present invention to provide a reenforcing bar of such structure that an its: use the'above objections and disadvantages areiovercome and wherein all external force applied to the cementitious'body 1s repelledby a resistance to compression of the cemcntitious bodyin all directions, thus offsetting the disintegration or loosening'of the reenforcing barin the body.

Briefly;stated, the present invention provides a reenforcing bar which is formed with a' lnokeu surface providing projections which are closely spaced-apart, which are so'formed at the faces of theprojections that all sides thereof are of equal area, and wherein the pro ections are so disposed upon the surface of the bar .toovercome any tendency of the bar to break along lmes between 'theprojections.

The above,and various other objects and advantages of thisinvention will be in part describechand in part understood, from the followin detaileddescription of the present preferred embodiment, the same being illus trated i-n'th e accompanying drawingwvherein Figure 1 is a side elevation, on an enlarged scale, of a len th of reenforcing bar constructed according to the present invention,

Figure 2 is a transverse section through the same.

Referring to this drawing, 10 designates a reenforcing bar which is preferably formed from metal, and which may, gen erally, be of any desired cross-sectional form, such as rectangular as shown in Fig. 2.

The surface or periphery of the bar is made up entirely of a plurality of nested projections 11 which may be pyramidal in form, and which have bases of substantially diamond formation. As shown in Fig. 2, the longitudinal axes of the bases of the projections 11 extend transversely of the longitudinal axis of the bar, the projections 11 being arranged in transverse abutting rows across the face of the bar, and each transverse row being nested in or intermeshing with its adjacent row at opposite Each projection 11 is provided with four sides .12, each having the nested together, the basic marginal edges of the sides 12 of the adjacent projections 11 are coincident, so that the peripheral surface of the bar is made up wholly of a multiplicity of the sides 12. The sides 12 are arranged at angles to one another, and are so arranged as to present abutting or hearing faces in all directions longitudinally and obliquely with respect to the longitudinal axis of the bar. Further, the interfitting and consequent offsetting of the transverse rows of projections 11 eliminate trans versely extending weakening grooves or recesses transversely of the axis of the bar so that when the latter is bent, as in the practice of fabrication, the tendency of the bar to break or crack is considerably lessened.

The entire surface of the bar is composed of a mass of the projections 11 so that resistance of the bar to movement in the cementitious body is transmitted by compression of the cementitious body, the inclined faces 12 serving as abutments which, under stress, compressive forces extending, as they do, in practically all directions, offer a direct resistance to the displacement of the bar.

Another feature of the present invention is that the projections 11 have their faces 12 of equal area to offer uniform resistance of the bar to displacement in opposite directions.

By the peculiar formation and arrangement of the projections 11, recesses or depressions are formed in the surface of the bar which are of the same size and shape as that of the projections 11, and which are adapted to receive the cementitious material therein. l/Vhen the material is set, the contacting face thereof presents a plurality of connected integral projections which are interbraced, and which interfit with the recesses in the surface-ofthe bar 10. Thus, the projections of the surrounding material about the bar 10, are not isolated from one another, and the body of the material presents no fiat faces substantially parallel to the axis of the bar which depend upon adhesion to the bar for maintaining the latter from displacement in the cementitious body.

It is of course understood that various changes may be made in the size and shape of the bar, the formation of the projections, and the arrangement of the same Without departing from the spirit of this invention, and being restricted only by the scope of the following claim.

I claim 2- A reinforcement for cementitious material comprising a bar having its exterior surface composed of interfitting'pyramidal projections with faces of equal area adapted to ofier uniform resistance to displacement in all directions, the base of each interfitting pyramidal projection being of substantially diamond shape and having each of its edges coincident with and common to the corresponding contiguous edge of the base of the adjacent interfitting pyramidal projection,

thereby, forming transverse and longitudinal rows of staggered projections adapted to elimlnate transversely extending weakening grooves and recesses.

HERBERT H. MUIR. 

